LOW ALLOY STEEL CONTAINING Mn AND Mo FOR WELDING FLUX HAVING IMPROVED IMPACT RESISTANCE AT LOW TEMPERATURE, TOUGHNESS AND TENSILE STRENGTH BY LOWERING CONTENTS OF C, Si AND Mn

摘要

PURPOSE: To develop a welding flux that is inexpensively fabricated and has superior weldability and corrosion resistance at high temperature so that the welding flux is suitably used for submerged arc welding low alloy steel containing Mn and Mo used in fabrication of atomic power pressure vessels. CONSTITUTION: The low alloy steel containing Mn and Mo for welding flux has a chemical composition comprising 0.056 to 0.068 wt.% of C, 0.136 to 0.203 wt.% of Si, 1.366 to 1.681 wt.% of Mn, 0.021 to 0.024 wt.% of P, 0.010 to 0.011 wt.% of S, 0.429 to 0.476 wt.% of Mo, 0.081 to 0.127 wt.% of Cu and the balance being Fe and inevitable impure elements that are not removable by the steelmaking refining process.